Translation and Psychometric Evaluation of the German Version of the Thirst Distress Scale for Patients With Heart Failure

BACKGROUND: In patients with chronic heart failure, thirst can be perceived as an intensive and burdensome symptom, which may have a negative impact on patients' quality of life. To initiate thirst-relieving interventions, assessment of thirst and its related distress is essential. At the time of this study, no instrument was available to evaluate thirst distress in patients with heart failure in Germany.

OBJECTIVE: The aims of this study were to translate the "Thirst Distress Scale for patients with Heart Failure" (TDS-HF) from English into German and to test validity and reliability of the scale.

METHODS: The English version of the TDS-HF was translated into German. A linguistically and culturally sensitive forward-and-backward translation was performed. Psychometric evaluation included confirmatory factor analysis, reliability in terms of internal consistency, and concurrent validity.

RESULTS: Eighty-four hospitalized patients (mean age, 72 ± 10 years; 29% female; mean left ventricular ejection fraction, 36% ± 12%; 62% New York Heart Association functional classes III-IV, 45% on fluid restriction) from an acute care hospital were involved in the study. The item-total correlation ranged from 0.58 to 0.78. Interitem correlations varied between 0.37 and 0.79. Internal consistency was high, with a Cronbach α of 0.89. There was a high correlation between the total score of the TDS-HF and the visual analog scale to assess thirst intensity (r = 0.72, P ≤ .001), and a low correlation with fluid restriction (r = 0.35, P = .002).

CONCLUSIONS: The evaluation of the German TDS-HF showed satisfactory psychometric properties in this sample. The instrument is usable for further research and additional psychometric testing.